Rabies is a viral disease that affects the central nervous system and is almost always fatal once symptoms appear. However, modern medicine has found ways to prevent death in some cases if treatment is started promptly. Here is an overview of rabies, how long you can expect to live after infection, and what factors influence survival.
What is Rabies?
Rabies is caused by lyssaviruses, including the rabies virus and Australian bat lyssavirus. It is spread through infected saliva, most often via animal bites or scratches. In rare cases, it can be transmitted through mucous membranes or open wounds.
The rabies virus travels through nerves up to the brain where it causes swelling (encephalitis). There it severely affects the central nervous system, causing symptoms including anxiety, confusion, agitation, hallucinations, excess saliva, trouble swallowing, and fear of water.
Eventually, it leads to coma and death when left untreated. Worldwide, rabies causes an estimated 59,000 human deaths annually.
How Long Can You Live After Being Infected?
Once a person begins showing symptoms of rabies, the disease is nearly 100% fatal. There are only about 35 documented cases of human rabies survivors worldwide, most having received intensive medical intervention.
Death usually occurs within 7-10 days after the first symptoms appear. However, the incubation period between the initial infection and onset of symptoms varies greatly depending on factors like:
- Location of the bite and amount of virus transmitted
- Distance the virus has to travel to the central nervous system
- Health of one’s immune system
On average, the incubation period is 1-3 months but can range from less than a week to over a year in rare cases. The shortest incubation period documented is 4 days while the longest is 6 years.
Incubation Period
In most cases, the incubation period lasts 1-3 months. During this time, there are no symptoms as the virus travels through the nerves towards the brain and spinal cord.
Factors leading to a shorter incubation period include:
- Bites on the head, face, or neck
- Severe bites that deliver a large viral load
- Infection directly into nerves or blood vessels
- Weakened immune system
Longer incubation periods are more likely with:
- Bites on the extremities like arms or legs
- Quick wound cleansing that reduces the viral load
- Strong immune response
- Medical interventions like vaccines or immunoglobulin
Survival Time After Symptom Onset
Once symptoms begin, rabies progresses rapidly and leads to death within 7-10 days in most cases. However, factors like age, health status, and prompt medical care can influence survival time.
Some key points about survival time after symptom onset:
- Death usually occurs within 2 weeks of becoming symptomatic.
- The shortest survival time is just 1 day after symptoms started.
- Young and healthy people may live up to 20 days.
- Intensive medical support can prolong life by several weeks in rare cases.
- Only 14 people have ever survived symptomatic rabies without intensive care.
Age and Health
Younger people and those in good health may live slightly longer with rabies symptoms compared to elderly or sick individuals. For example:
- A 3-year-old girl survived for 7 days after developing symptoms.
- Some teenagers lived for up to 20 days before succumbing.
- Elderly people or those with impaired immune function often die within 6 days.
Stronger immune function in the young and healthy may slow disease progression briefly. But rabies remains highly lethal once signs appear regardless of age or medical history.
Medical Intervention
With intensive and prompt care, doctors have prolonged the lives of a handful of rabies patients by up to several weeks. This can buy time for immune responses to develop in some cases.
Treatment efforts focus on managing symptoms, preserving brain function, and enabling the immune system to fight the virus. This may involve:
- Medically induced coma
- Antiviral drugs
- Immunotherapy
- Supportive care like IV fluids and nutrition
To date, less than 15 people have ever survived after developing rabies symptoms, even with top-level hospital care. Modern medicine still cannot cure rabies once clinical signs appear.
How Does Rabies Progress?
Rabies develops in two phases – the incubation period followed by a shorter acute period where symptoms rapidly worsen. Here is an overview of how the disease typically advances:
Incubation Period
The incubation period lasts 1-3 months on average. During this time:
- The virus multiplies at the wound site and travels through nerves to the brain and spinal cord.
- No signs or symptoms are present.
- Standard blood and saliva tests cannot detect the virus yet.
Once in the central nervous system, the virus begins causing inflammation.
Prodromal Phase
Early symptoms like fever and headache mark the beginning of the prodromal phase, which lasts 2-10 days. Other possible signs include:
- Malaise
- Nausea
- Vomiting
- Agitation
- Anxiety
- Confusion
- Abnormal sensations at the wound site
These milder initial symptoms often lead people to think it is a more common illness like the flu. But rabies continues progressing towards the next phase.
Acute Neurologic Phase
After the prodromal phase, more specific neurologic symptoms appear signaling the onset of the acute phase. This lasts just 2-7 days as rabies rapidly worsens. Neurologic signs include:
- Hydrophobia – fear of water
- Aerophobia – fear of air drafts
- Agitation
- Hallucinations
- Seizures
- Paralysis
- Difficulty swallowing
- Excess saliva
The infection spreads throughout the central nervous system. As critical functions fail, life-threatening complications ensue like respiratory arrest, seizures, and coma preceding death.
Can Rabies Be Cured?
There is no effective treatment for rabies once clinical symptoms develop. Palliative care focuses on easing discomfort in the terminal stages.
However, rabies can be prevented if treatment is started before symptoms arise. Two options can stop the virus and save lives:
Post-Exposure Prophylaxis (PEP)
PEP involves wound cleaning and a regimen of rabies vaccines plus immunoglobulin injections for previously unvaccinated individuals. This stimulates the immune system to neutralize the virus before it reaches the central nervous system.
PEP is highly effective if administered promptly within 5-7 days after suspected rabies exposure. Survival approaches 100% for those receiving timely PEP.
Pre-Exposure Vaccination
The rabies vaccine can also be given as a precautionary measure before virus exposure. This primes the immune system to mount a faster response if exposed to rabies later on.
Pre-exposure vaccination does not eliminate the need for PEP after a bite. But it simplifies treatment to just two vaccine boosters rather than the full series plus immunoglobulin needed in previously unvaccinated people.
Pre-exposure vaccination is recommended for high-risk groups like veterinarians, animal handlers, certain laboratory workers, and travelers to areas with endemic rabies.
Can Rabies Be Cured Once Symptomatic?
Unfortunately, no effective treatment exists for rabies once symptoms appear. Intensive hospital care has prolonged survival temporarily in a handful of patients, but rabies remains almost universally fatal at this stage.
Barriers to curing symptomatic rabies include:
- Difficulty delivering antivirals to the brain and spinal cord.
- Poor understanding of how rabies evades immune defenses.
- Irreversible damage inflicted on the nervous system.
- The rapid progression giving little time to intervene.
Research continues, but doctors emphasize that prevention via vaccination remains the only proven way to avoid a fatal outcome after rabies virus exposure.
Experimental Treatments
Some emerging experimental treatments aim to cure rabies in symptomatic patients, but none has yet proven successful alone:
- Immunotherapies – Treatment approaches that harness the immune system like antibodies or immune modulators. Shows promise enhancing immune activity against rabies in animal models.
- Antiviral drugs – Medications that impede viral replication. They have exhibited anti-rabies activity in lab studies but less benefit in human cases so far.
- Ketogenic diet – Restricting carbohydrate intake and inducing ketosis has shown limited potential to prolong survival in a small number of studies.
- Physiotherapy – Therapies like nerve stimulation aim to reverse peripheral nerve dysfunction caused by rabies. Outcomes are uncertain at this point.
Current evidence does not indicate any standalone treatments can cure rabies once symptoms manifest. Combination therapy offers the most hope for finding an effective regimen in the future.
Can Rabies Be Prevented?
Prevention is the only proven way to reliably avoid a rabies death. Fortunately, very effective preventive measures exist including:
Pre-exposure Vaccination
Getting vaccinated before any known rabies exposure provides proactive protection. It requires a 3-dose vaccine series over 21-28 days plus a booster after 1 year.
Pre-exposure vaccination is recommended for:
- People at high risk like veterinarians, animal control staff, some laboratory workers, and travelers to areas with endemic rabies
- Children living in or visiting areas with stray dog rabies transmission
Post-Exposure Prophylaxis (PEP)
PEP combines wound treatment, a dose of rabies immune globulin, and 4-5 vaccine doses over 14 days. This can prevent infection after exposure to rabies.
PEP should begin promptly after possible rabies contact like an animal bite. The sooner treatment starts, the better the chance of success. Guidelines recommend beginning PEP within:
- Immediately up to 3 days after exposure for the best protection
- 4-7 days for very high likelihood of prevention
- Up to 10 days for possible benefit
PEP averts rabies in almost 100% of cases when administered in a timely manner. It saves an estimated 40,000 lives worldwide each year.
Other Precautions
Additional ways to prevent rabies exposure include:
- Avoiding contact with wild animals like raccoons, skunks, foxes, and bats
- Keeping pet vaccinations up to date
- Preventing stray animals from accessing food or shelter around the home
- Reporting unusual animal behavior to authorities
- Treating animal bites immediately by washing with soap and water
Rabies Statistics and Facts
Here are some key statistics and facts about rabies:
- Less than 20 human rabies cases occur in the U.S. each year
- Around 59,000 people die annually worldwide, mostly in Africa and Asia
- Over 95% of cases result from dog bites
- Signs can begin as soon as 4 days or up to 8 years after infection
- Rabies has the highest mortality rate of any infectious disease – close to 100% once symptoms appear
- Survival is extremely rare once clinical signs manifest, even with intensive care
- Infection is fully preventable through timely vaccination and prompt wound care
Frequently Asked Questions
How long can you live with rabies untreated?
Without any treatment, rabies typically leads to death within 2 weeks of symptom onset. Only about 14 people have ever survived longer than 1 month after developing symptoms without intensive medical intervention.
What are the chances of surviving rabies?
Once clinical signs appear, rabies has a nearly 100% fatality rate globally. Less than 15 people have survived symptomatic rabies, mostly with placement in a medically induced coma plus strong ICU support. Overall survival odds are extremely low if rabies is not prevented.
Does rabies kill you instantly?
No, rabies does not immediately cause sudden death. Early flu-like symptoms evolve over 2-10 days into more serious neurologic deficits. Ultimately rabies leads to coma and respiratory dysfunction over a week or two after signs start.
How painful is rabies?
Rabies can cause moderate discomfort like headaches, fever, nausea, and paresthesia in the early prodromal phase. As neurologic symptoms appear, more severe pain is rare but agitation, seizures, muscle spasms, and paralysis can occur in late stages.
Is there a test for rabies?
Yes, samples of blood serum, skin, saliva, and spinal fluid can be tested to detect rabies virus antibodies or antigens. However, tests may not pick up early infection during the incubation period. Repeated testing over time is recommended after a potential exposure.
Conclusion
Left untreated, rabies is almost always fatal within a month of symptom onset. While a handful of human survivors give hope, survival remains extremely rare once clinical signs appear, even with strong medical support.
Fortunately, rabies can be readily prevented through modern vaccines for those at risk. This lifts the death sentence that rabies carried for millennia. By raising awareness and expanding access to prophylaxis worldwide, the goal is eventual global elimination of this feared ancient disease.